RO Unit Mod

Ive been using a basic 3 stage Coralife 50gpd unit. 2 months ago I added a 4th chamber for Deionization. But a month ago a broke down a 240gal system and bought everything he had, including a 2nd 3 stage 50gpd unit. My question is how can I combine the 2 3 stagers into one super water polishing RO filter? Im thinking about using the separate 4th stage DI chamber with my calcium reactor. Ive heard you can use another chamber to increase the ph before the effluent reaches the tank.

Combining the 2 3 stagers together doesnt appear to be an issue. Ill ust bypass the membrane housing on the second one and use the two chambers for DI resin.

I was also thinking about buying some of this bulk DI resin I see being offered here and there. Maybe I could just use my old, depleted mixed bed cartridge and just replace the resin?

If anyone has any thoughts on how to make a really effective 5-6 stage unit using what I have I would love to hear it. Ive seen other RO units that have a total of 3 stages before the water reaches the TFC membrane? I believe the 3rd is used to remove every last bit of chlorine before it damages the membrane. Could something like that be done? Id forget about my Ca reactor plans and just use the singular chamber for this chlorine busting deal.

Can I save money on a replacement TFC membrane without sacrificing purity?

Its alot of questions I know, but If i could just get some solutions to one or two it would help greatly. TFC membrane and DI cartridge are done and Ive been buying water until I figure this out.

 

The number of stages doesn't mean a hil of beans, its what the stages contain that makes the difference. For a killer reef quality RO/DI system you only need 4 stages period, 1 low micron prefilter, 1 low micron carbon block, 1 high quality RO membrane and 1 full size 20 oz vertical DI canister and refillable cartridge, thats it.

By whats in them I am referring to high quality low micron replacement filters such as a 0.5 micron absolute rated prefilter that really does a good job of protecting the 0.5 or 0.6 micron carbon block so it can do its job of removing chlorine and VOCs and not acting as a secondary prefilter like most vendors provide them. Carbon blocks are made up of bilions of tiny microscopic pores which is what adsorbs the chlorine and organics, if its trapping particulates the surface and pores get plugged or fouled and its worthless. Protect the carbon block with a good prefilter of 1 micron or less, preferrably equal to the carbon or smaler micron rating, I use a 0.2 micron pleated prefilter that has 10x the surface area of normal filters, filters better, lasts much longer and provides lower pressure drop too.
You do not need or want multiple carbons, most provide two for the reason I explained above, one is acting as a prefilter and is worthless, forget that one. Using a high quality Chlorine Guzzler in the 0.6 or 0.5 micron range you get a full 20,000 gallons of capacity for chlorine and they are extremely effective on the chlorine portion of chloramines too. No need for granular products or high micron carbons.

The membrane is the workhorse of the system and needs to be as efficient as possible or you pay for DI replacements. I use the Select series from Spectrapure which are on sale for $45 for a 90 GPD membrane right now. Thats a bargain for an individually hand tested and guaranteed 98+% rejection rate RO membrane. They are tested and treated with a proprietary process to improve both production rate and rejection rate and carry the testers initials right on the package. No one else guarantees their membranes like that. I am geting about 99.35% rejection out of mine. That is important when you consider for every 2% you increase the membranes efficiency, you DOUBLE the life of your DI resin. That can be a very big cost savings over a years time, often paying for itself in less than a year.
Be careful with many bulk DI resins. DI resin has a shelf life, even when hermetically sealed. Never buy more than you can use in 6 months and then store it sealed with moisture in it inside the refrigerator. If it drys out its not much good. Using the Select membrane I get about 5 times the life out of my DI now compared to when I was using an off the shelf Dow Filmtec membrane and bulk DI resin, no matter whcih resin I used previously. I also use Spectrapures SilicaBuster and MaxCap DI resins which can be bought in bulk now which gives me even more DI life.

Remember its what inside the stages not how many there are, in fact multiple stages can lead to higher pressure loss which reduces both GPD and rejection or removal efficiency.

All the things I have mentioned are on sale here:
SpectraPure Customer Appreciation SALE! 20% - 50% off
but I did not intend this post as a sales pitch, only to comment on the importance of good filters in the correct sizes. More is not necessarily better except for multiple DI stages which do have a proven benefit with the right resins.

Another thing is you can combine the two membranes for increased production but I would test them for removal efficiency first. If they are not at least 96+% rejection I would think about a single 90GPD membrane or even dual 90GPD membranes for a kiler 180 GPD system using the components you already have plus a few minor fittings and two new membranes. I used to have a dual membrane system that produced 240 GPD at 99.23% rejection rate and it was a killer system!

 

Man.. is this a premade masterpiece of RO advice you paste now and again? Cuz it was extremely informative and its rare to get well written replys banged out like that.. I have a question right off the top though. This 90 gallon per day TFC membrane you got, that wont work in a Corallife Pure-Flo II 50 gpd unit will it? If not where can I get a quality membrane for my unit that wont cost too much. Until I read your post I figured Id have to pay no less than $75 for it.

Cant I just use the two connected chambers of the secondary unit for something useful though? Either to doubly filter the water before it reaches the membrane, thus prolonging life of carbon and tfc. Or have two final polishers after the membrane with DI? .. you answered that already I guess. The problem Im having is 1) I have alot of spare parts to use in a "super filter" just laying around and 2) Its just hard to believe all these people spending big bucks 5 and 7 stage filters are wasting their money. What you say sounds plausible enough, the usual 3 plus the DI addon I have.

Bottomline is I finally got a 100+ gallon storage facility ready, but somethins screwed up with the cartriges and im assuming they are depleted. I now wanna replace what I have to but make sure I get the most life out of the new cartridges while storing a months worth of the best possible water. Tell you what man if you read this just tell me what you'd do with 2 Corallife Pure Flo II's and Ill follow it. If you say get the Spectrapure filters and use one of their DI canisters as a fourth and final stage, Ill do it. Just trying to think outside the box, use what I have and maximize quality and longevity.

Thank you again sir..

 

K I reread your post and I guess nvm my previous post.i just have to get 4 good filters. I have 2 corallife microns and 2 corallife carbons. Just need the good TFC and DI and if I could save a little money with them then great.

 

Coralife replacement filters are not very good quality, do you even have any idea the micron ranges or the chlorine adsorption capacity? I think they are pretty low end if I remember right
The Select membrane wil fit in your housing, all you need is a new membrane and a $5 flow restrictor to go with it, $50 total for the two pieces with their sale price I linked to.
If it were me I would get a 0.5 micron prefilter at $12, a 0.5 micron carbon block at $13, a MaxCap DI cartridge at $27 and a SilicaBuster DI at $18 along with the new membrane and flow restrictor. Thats $120 for everything and basically gets you into a MaxCap RO/DI which normally sells for about $350.
Use the housings you already have for everything by adding the extra two canisters and bracket after the RO membrane for the dual DI cartridges. If you only want a single DI then get just the SilicaBuster DI cartridge or even bulk SilicaBuster resin if you have a refillable cartridge already but it sounds like what you had was RO only so you probably need the refillable cartridge.
Don't buy a good membrane and use the Coralife filters in front of it, it wil not last nor perform as well due to their quality. The prefilter and carbon are there solely to protect the membrane which is the workhorse. Spectrapure is unique in that they enginner a complete system start to finish, it takes each piece to make the unit work as system and last like they do. Randy Holmes Farley recently reported 1o years life out of a single Spectrapure RO membrane which is unheard of with other brands and its mostly due to superior prefiltration. It ends up saving you money in the long run.

Don't add more filters in front of the membrane, its usually counterproductive.

 

Awesome man TY.

 

I just erased my rambling and made a new thread on this